The present invention relates to an exchangeable adapter for open-end spinning arrangements for reducing a trash removal opening of an opening roller housing, said adapter comprising two semi-circular supporting surfaces for clamping the adapter onto corresponding curved countersurfaces, also comprising a curved fiber guiding surface corresponding to the curve of an opening roller, and comprising a boundary wall for reducing the size of the trash removal opening, said boundary wall being arranged directly upstream of the fiber guiding surface.
Trash removal openings in opening roller housings for open-end spinning arrangements are standard in the industry today. They serve on the one hand to separate the trash particles from the opened fiber material. On the other hand, the trash removal openings are simultaneously used as openings to feed in the necessary air required for the spinning process. Both processes are known in the spinning industry. It has been shown, however, that such trash removal openings can present unnecessary problems in the transport of some fiber materials, in particular when relatively clean fiber material is to be spun or when the opened single fibers are so short that there is a risk that fiber material will also be expelled. In particular in the processing of linen or regenerative material, trash removal openings can present a problem.
It was known early on in German published patent 19 22 078 to provide trash removal openings with a regulatory closing piece which is adapted to the shape of the wall of the opening roller housing and with which the trash removal opening can be partly or entirely closed.
It is known in German published patent application 42 25 668 to border the trash removal opening on its exit side with a trash guiding wall which can be swivelled. By means of positioning the trash guiding wall at different angles, various air currents are known to be produced.
Both these variations are very complicated and have not found any place in practical use.
An exchangeable adapter for open-end spinning arrangements for reducing the size of a trash removal opening of an opening roller housing is known from prior notorious use in a machine built for use in the spinning industry, said prior use being undocumented. The preamble of the main claim of the present invention is based on such an adapter. The known adapter comprises two semi-circular supporting surfaces arranged at a distance to one another, with which the adapter can be clamped onto corresponding curved countersurfaces which border a trash removal opening on its exit side. The known adapter comprises a curved fiber guiding surface with corresponds to the curve of the opening roller, which fiber guiding surface extends the periphery wall of the opening roller housing surrounding the opening roller, thus reducing the size of the trash removal opening. The known adapter comprises further a boundary wall, arranged directly upstream of the fiber guiding surface, at the end of the trash removal opening.
Exchangeable adapters of this type can be applied to the opening roller housings as required or removed therefrom. This can be done by hand, and as a rule, tools are not needed. The known adapter has the disadvantage, however, that because of its method of fabrication, it is not suitable for being produced in large numbers, as it is made by means of milling its contours. It is also not suitable for permitting the feeding of air outside of the reduced trash removal opening.
It is an object of the present invention to create an adapter of the above mentioned type, which can be manufactured cost-effectively in large numbers, and which also permits the feed of air for the spinning process if required.
This object is achieved in that the adapter is fabricated from profiled bars and cut to match the required effective width of the fiber guiding surface and the boundary wall.
In the case of the profiled bars, an extruded, open profile made of light metal is preferably involved here, which comprises the necessary outer contours. These comprise on the one hand the necessary supporting surfaces for clamping the adapter onto countersurfaces as well as the necessary fiber guiding surface and the boundary wall. The profiled bars, produced in long lengths, are cut according to the required effective width of the opening roller housing, whereby minor re-working, for example, deburing, is subsequently necessary on the front sides. The effective width of the fiber guiding surface and the boundary wall have such dimensions that the adapter can be inserted flush between the lateral walls of the opening roller housing. Due to the special method of production, the supporting surfaces are as wide as the fiber guiding surface and the boundary wall. The profile is so designed that the fiber guiding surface graduates into boundary wall with a distinctive radius.
As exchangeable adapters according to the present invention can be manufactured cost-effectively in large numbers, it is possible to have adapters with various profiles to hand in a spinning mill. For example, a complete set of different adapters can be provided with which the trash removal opening on the opening roller housing can be reduced in size in a variety of ways.
Independently of the manufacturing process, that is, also applicable with the known adapter, it can be provided that the fiber guiding surface is provided with a recess which permits the entry of air, said recess being connected to the external atmosphere. Thus a type of by-pass opening is created which generates, in addition to the air fed through the trash removal opening, a further opening for the feeding of additional air for the spinning process, but without any fibers being expelled therefrom.
As expelled trash particles travel at a high speed and are very aggressive, it is advantageous when the fiber guiding surfaces and the boundary wall of the adapter, including the transition area between them, are provided with a wear-resistant coating.
If the bars do not consist of light metal, but rather are made from a plastic injection moulded part, a coating for the prevention of wear on the surface is indispensable. The coating can be a metal alloy or ceramic.
As the opening roller, provided with a needle or saw-toothed combing means, and located in the opening roller housing, can hinder the removal of the adapter, it can be advantageous in a further embodiment of the present invention when the adapter is provided with a web on its side facing away from the fiber guiding surface, said web comprising an engaging surface for a removal tool. In the case of such an engaging surface, a simple bore hole can be involved here. In the case of an appropriate embodiment of the adapter and its supporting surfaces, dismantling the adapter can, as a rule, take place without the use of a tool. The bore hole can serve at the same time to connect the above mentioned recess to the external atmosphere.